1. Field of Invention
This invention relates to the command operation to draw graphics by a graphic processing system.
2. Description of the Prior Art
Conventionally, the commands for drawing graphics by a graphic processing system have one operation with regard to the procedure for inputting of parameters and offer one function as result of the command execution. Therefore the number of commands will be increased whenever a new function is added. As a result, there will be a number of commands which have similar functions but different operations and different names.
For example, when an operator uses a basic command to draw a circle, he/she must consider the following before selecting one basic command;
(1) I want to draw a circle. PA1 (2) Where shall I draw a circle on the screen. PA1 (3) To draw the circle do I indicate the center of the circle?
or do I Indicate a point on circumference? PA2 or do I draw a tangent circle touching to a line drawn already? PA2 (4) To draw the circle of a desired size, do I indicate a radius of a circle? PA2 or do I indicate a point on circumference? PA2 or do I draw a tangent circle touching to the line drawn already?
In the process of considering the above procedures, it is realized that there exist a number of methods to draw circles and a number of commands corresponding to such methods. When selecting the command based on the procedures, the operator ordinarily must identify a corresponding command from a menu which is displayed on a screen showing several commands, many having names which are similar but not identical.
As has been described, the number of commands in conventional graphic processing systems will increase as the number of functions is increased. The operator must select an appropriate command to execute each function, even though there may be two or more commands having similar functions. Moreover, the operator has the problem of Identifying an appropriate command among numerous similar commands.
Accordingly, these problems result in an increased number of operation procedures and more complicated and confusing operations.